Q.Knock out Rose bushes
Can the knock out roses be planted by holly bushes and how far to space them?

In part, the answer depends on what type of holly you have. A few like very moist, if not wet, soil - not rose friendly. Many varieties of holly sucker and may encroach on the roses if these aren't promptly removed. Place the holly where they won't shade the roses unless you are in the south where 2-3 hours of late afternoon shade won't harm the roses. Space the plants so there is ample room for the mature size of both plants otherwise they will compete for nutrients and a crowded rose will be more susceptible to foliar disease without good air circulation.